ANNAPOLIS - A divided Court of Appeals ruled Friday, October 19, that police need only reasonable suspicion to pull a car over, a lower standard than probable cause.

But the court ruled that a Harford County deputy sheriff did not even have reasonable suspicion when he pulled over a car in May 2006 because its rear window appeared "darker than a normal window."

"The court for the first time has held that reasonable suspicion is the standard for when a car is stopped in the state of Maryland," said Lisa Sansone, lawyer for Arvel Williams, the driver in the Harford County case. "Prior to that there was some confusion as to whether probable cause would be required."

The case began early on the morning of May 8, 2006, when the Harford County Sheriff's Department was on the lookout for a black Mercury Grand Marquis that authorities believed may have been carrying drugs.

A deputy who saw a Marquis with license plates that matched the description of the suspect vehicle followed it off Interstate 95 and pulled up behind it at a red light in what he said was a well-lit area.

At that point, the deputy noticed that the car's rear window seemed tinted and he later testified that he pulled the Marquis over because the window seemed darker than normal.

The deputy found that Williams had a valid license and no warrants, but he did start writing a repair order for the rear window. While he was doing that, another officer arrived with a drug-sniffing dog that indicated the possible presence of drugs in the Marquis. A subsequent search turned up suspected cocaine and marijuana.

"The police have really started using this as a pretext to pull a car over," Sansone said. "Now many of them may be thrown out."

State law says tinted windows must allow at least 35 percent of the light to pass through. While there are instruments that can measure whether a tinted window complies with the law, the Harford deputy did not have one and did not know how to use one. He testified only that the window was darker than a normal window.

"Obviously, a tinted window is going to appear darker than a window without any tinting, especially at night," the court said in Friday's opinion.

Williams took the car four days later to the State Police Automotive Safety Enforcement Division, which found that his windows were not illegally tinted.

A Harford County circuit judge ruled that, because the windows were not illegally tinted, the drug evidence could not be used in Williams' trial. The state appealed, leading to Friday's opinion.

The appellate court ruled that the officer needed reasonable evidence showing the level of tinting exceeded legal limits, which he could not provide. If an officer were allowed to stop and search car without such reasonable evidence, "it would effectively strip away Fourth Amendment protection for any person owning or driving a car with tinted windows."

In a dissent, three judges agreed that the deputy needed only reasonable suspicion to stop Williams. But they believed he did have cause to believe the window was in violation, citing the fact that the deputy did not see an inspection sticker on the rear window that would identify it as being in compliance.

Judges Robert Bell and Clayton Greene Jr. agreed with the majority opinion on the facts of the case, but disagreed with the rest of the court's conclusion that an officer could make a traffic stop without probable cause.